Dr. Rippe's Blog

When I mention weight loss diets that focus on single foods, you probably know what I'm talking about. For example, the "grapefruit diet" and the "cabbage soup" diet are two of the oldest. And they have many variants--just Google either term and see how many hits you get. Each season there are several new diet books or programs that claim to have found a new way to lose weight quickly by targeting a particular food or food group. Will such diets help you lose weight?  In the short-term, yes--almost any diet that reduces the calories (energy) you consume each day will enable you to lose weight. Proponents of such diets may claim all sorts of reasons why such diets work, but research shows that the main reason they work is that if you follow their plan you consume fewer calories daily than your body burns.  If you have to eat mainly grapefruit or cabbage soup all day, for example, who wouldn't consume fewer calories, at least after a day or two.

Of course, that example is an extreme. Most diets that focus on limiting intakes of certain food groups do include more food groups than one or two. The question to consider, however, is whether the diet is helping you adopt a balanced nutritional approach to healthful eating that you can maintain for the long-term? Is it helping you learn to prepare tasty, balanced recipes that you and your family can enjoy after you've met your weight loss goals. If it doesn't, then you may experience successful weight loss in the short-term but not be able to maintain that loss over the long-term. Then it's back to another diet. Such weight cycling, or "yo yo dieting," over time tends to make it harder to lose weight and sustain that loss. The loss of muscle tissue along with fat tissue through such dieting, particularly if you don't get regular physical activity, slows metabolism.

When you're looking for a weight loss diet, I recommend that you look for a plan that will help you reduce energy by about 500 calories a day, while maintaining balanced nutrition. You can use the Balanced Eating Plan on this website to design such a plan customized to your individual likes and needs. Also don't forget to get regular physical activity. Walking daily will help you keep your metabolism revved up while you lose weight.

In recent weeks, I've seen a couple of popular articles that suggested that exercising as part of a weight loss plan is a myth--at least their headlines suggested that. A dip into the articles showed that the writers understood that the reality of the matter is more complex.

As I noted in my last post, there is one basic law of weight loss--you must burn more energy (calories) than you eat if you want to lower body weight.  You can do that by eating fewer calories than your body burns to fuel life--we call that dieting.  Or you could exercise furiously for a good bit of time each day to burn significantly more calories through activity than you are eating. Of these either-or alternatives, research shows that dieting alone for at least the short-term leads to more weight loss than exercise alone. But research shows that the most effective strategies for weight loss aren't either diet or exercise; they include both.  Let's look at why.

If you want to lose weight and keep it off, what kind of weight within your body do you wish to lose? Water weight? No, that's what you typically lose in the first few days of a crash diet.  Water weight comes right back. Lean muscle tissue? No, lean muscle is the body's metabolic engine--the more lean muscle you have, the more calories you burn and the more efficiently you burn them. So you want to hang on to your lean muscle or even build it up as you lose weight. Fat tissue? Right!  The goal for effective weight loss that you can maintain for the long-term is to lose body FAT.

The best way to target body fat tissue for loss is to consume a reduced calorie diet while getting regular physical activity. A diet that provides balanced nutrition while reducing calorie intake about 500 calories daily below what you need to maintain your current body weight is a good goal. Now, you can lose weight just dieting this way. But your body will tend to burn both fat tissue and lean muscle as you lose weight.  Losing lean muscle sets you up for yo-yo dieting.  You can prevent this by adding daily, moderate activity such as walking for 30 to 45 minutes each day.  If you enjoy strength training, you can do this on two or three days a week.

So where's the catch?  One catch is that we tend to think that if we are physically active we can eat what we like.  We overestimate the amount of calories that activity or even heavy exercise burns. If you weight 180 and hit the treadmill for a vigorous 30 minutes then go out an eat a muffin and latte at the coffee shop, you'll gain weight. Why?  You burned only 130-160 calories on the treadmill. But that medium blueberry muffin had about 300 calories and we won't even go into what you put in the latte.  One reason to go for moderate activity such as walking, rather than a vigorous workout, is that you are less likely to be really hungry after the activity. If you need a snack, make sure to have some fresh fruit or vegetable sticks at hand.

Some here's the important tip: You aren't getting regular physical activity to lose weight. You're getting regular physical activity to help you maintain and build lean muscle mass so that your body will burn fat on your reduced calorie diet and you'll be more likely to keep the weight off.

As I look over recent titles in bookstores, banners on magazine covers at airport newstands, or the promos for talk shows, not to mention a barrage of print and broadcast ads, I'm convinced once again that Americans' quest for "easy" weight loss keeps a variety of businesses afloat. If you are serious about losing weight and keeping it off (and most people really do want to achieve a healthy weight), then this often conflicting barrage of unfiltered "information" can be confusing. Losing weight or maintaining a "normal" weight status, particularly as we get older, is hard. Who wouldn't be tempted by the idea that following a special eating plan that emphasizes a particular food or food group would help one lose 30 or 40 pounds in four or six weeks? Or what about that idea that you could take a pill and go to bed and it would work overnight to rev up your metabolism and help you lose weight without changing a thing? Tempting as they may be, such approaches to weight loss are short-term at best and just myths (a few possibly harmful myths) at worst.

Over the last twenty-five plus years, my research clinic has conducted hundreds of scientific research studies on weight management that have involved thousands of participants. Our research team has also stayed abreast of thousands of other scientific studies. Although science continues to probe and learn important facts related to nutrition, physical activity, human physiology and genetics and weight gain or loss (among many other aspects), the basic mechanisms of weight gain and weight loss and maintenance of weight loss are well understood. Although each of us is an individual, our weight status depends on our balancing the energy we eat with the energy we expend in the activities of daily life. Specific health conditions or genetic/physical conditions might affect how your body uses energy, but the energy balance equation is valid for all of us: Energy intake must be balanced by energy expenditure to maintain a steady weight. Take in more energy than you expend, gain weight. Expend more energy than you take in, lose weight.

Things get a little complicated for most of us when we try to manage weight because we tend to underestimate the energy we take in and overestimate the energy we use in the activities of daily living and through planned physical activity. That's why the most effective weight loss plans typically have you keep records that record daily intakes/activities or have you follow a specific set plan. Such set plans or tracking schemes help you realistically balance your energy intake and energy expenditure.

Although individual studies may appear contradictory, the overriding preponderance of scientific evidence indicates that the most effective approach to long-term fat weight loss for the majority of people is to combine a reduced calorie diet with a plan for increased physical activity.  Reducing intake of calories by about 500 fewer calories per day than the amount of calories required to maintain your current weight leads your body to burn stored energy. Adding physical activity to the mix helps your body maintain lean muscle ( the body's metabolic engine or "calorie burner") and helps weight loss come from stored fat not lean muscle. The most successful weight loss plans or approaches (and there are a variety) build on these principals.

In the next couple of weeks, I'm going to talk about what stumbling blocks many people (and more than a few "diet plans") run into in trying to implement this principle.  And we'll look more specifically at the traps of some specific weight loss myths.